Diagnosis Method to Detect the Incorporation of Metallic Particles in a Lithium Ion Battery

Lithium ion batteries have the issue of internal short-circuiting by the cathodic electrodeposition of metal at the negative electrode during charging. This deposition follows the anodic dissolution of metallic particles incorporated into the positive electrode in the manufacturing process. Thus, we have investigated the dissolution and deposition behaviors of metals including copper, nickel, iron, and stainless steel using cyclic voltammetry and scanning electron microscope/energy dispersive X-ray spectroscopy. We have also addressed the diagnosis of the incorporation of the metallic particles and metal depositions by electrochemical impedance spectroscopy, focusing on the time variation of the Bode plots of the phase angle around 10 - 1 Hz, where we detect characteristic variations depending on the number of the incorporated metallic particles.